Syrian tanks tightened their occupation of Hama and massed outside a defiant city in the east as President Bashar al-Assad ignored mounting world condemnation of attacks on protesters the United States says has killed 2,000 people opposing his rule.

Syrian military and security forces stormed Hama and other restive cities before dawn on Sunday, killing at least 75 people in what appeared to mark the fiercest crackdown yet by the government of President Bashar al-Assad on the four-month old uprising against his rule, activists and residents there said.

Syrian troops and militiamen loyal to President Bashar al-Assad killed 16 people in attacks in the city of Homs on Tuesday, residents said, an escalation of a crackdown against a focal point for pro-democracy protests.